An interventional study of distal iPACK and proximal iPACK in Postoperative Pain Following Knee Arthroplasty, sponsored by Comenius University. Recruiting at 1 site in Slovakia. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-02-04.
Sponsored by Comenius University · Not applicable, Interventional, and Treatment
Total knee arthroplasty (TKA) often results in significant postoperative pain, which can hinder recovery despite advances in surgical and anesthetic techniques. Traditional pain management methods like femoral nerve blocks may impair motor function, delaying rehabilitation. The iPACK block, targeting the posterior knee without affecting motor control, offers a promising alternative. This study aims to compare the effectiveness of two iPACK block approaches-proximal (at the distal femoral shaft) and distal (between the femoral condyles)-in managing postoperative pain in TKA patients. In a double-blind, randomized controlled trial with 120 participants, pain scores, opioid use, and time to rescue analgesia will be assessed. The hypothesis is that the distal iPACK block provides superior pain relief, potentially improving patient outcomes and recovery.
Total knee arthroplasty (TKA) is one of the most frequently performed orthopedic procedures in modern medicine. Despite advancements in surgical techniques and perioperative care, postoperative pain management remains a significant challenge and a key factor influencing time to mobilization, patient satisfaction, and length of hospital stay. Commonly used analgesic techniques, such as femoral nerve blocks or epidural analgesia, while effective, can impair motor function and thus delay rehabilitation.
To minimize motor deficits while still providing effective pain relief, newer regional anesthesia techniques have been introduced into clinical practice. One such technique is the iPACK block (interspace between the popliteal artery and posterior capsule of the knee), which targets the posterior knee - an area often insufficiently covered by conventional nerve blocks. This method involves administering a local anesthetic into the space between the popliteal artery and the posterior capsule of the knee joint, offering analgesia without significant motor impairment.
Originally, the iPACK block was described as being performed at the level of the distal femoral shaft, several centimeters above the femoral condyles. Recently, however, a more distal variation of the technique has emerged, where the anesthetic is injected directly between the femoral condyles. This may provide more effective coverage of the posterior knee capsule's innervation. To date, there are no randomized trials that directly compare the efficacy of the distal and proximal iPACK approaches in terms of postoperative pain as the primary outcome.
Our aim is to conduct a prospective, randomized, placebo-controlled, double-blind clinical trial to compare the effectiveness of the distal and proximal iPACK blocks in patients undergoing TKA. A total of 120 patients will be enrolled and randomly assigned to one of two groups.
All participants, regardless of group assignment, will also receive an adductor canal block with 20 ml of 0.25% levobupivacaine without adrenaline. In addition, all patients will receive standard analgesic therapy consisting of paracetamol (1 g IV every 8 hours) and diclofenac (75 mg IV every 12 hours). If necessary, rescue opioid doses will be available according to individual needs.
The efficacy of each approach will be assessed using several parameters: total opioid consumption within 24 hours and time to first opioid rescue dose, Visual Analogue Scale (VAS) both at rest and during active knee movement (up to 45 degrees) at 6, 12, and 24 hours postoperatively.
The hypothesis of our study is that the distal iPACK approach will provide more effective postoperative pain control compared to the original proximal technique. If confirmed, the findings could influence perioperative pain management protocols for TKA, support the broader adoption of the distal iPACK block in clinical practice, enhance patient comfort, reduce opioid use, promote earlier mobilization, and potentially shorten hospital stays.
5,640 studies on the registry are indexed under Pain, Postoperative; 1,230 are open to participants now.
This study's planned enrollment of 120 is above the median of 75 across 4,821 interventional studies indexed under Pain, Postoperative.
Browse Pain, Postoperative studies →Comenius University is the lead sponsor of 42 studies on the registry; 11 are open to participants now.
Compared within Pain, Postoperative, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Pain. The counts are of registry records indexed under each term, refreshed daily. How we classify →
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
A score of how well the liver works in people with liver disease such as cirrhosis: class A is mild, B moderate and C severe.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Child-Pugh class
A score of how well the liver works in people with liver disease such as cirrhosis: class A is mild, B moderate and C severe.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
In the proximal iPACK group, participants will receive 20 ml of 0.25% levobupivacaine with adrenaline (1:200,000), injected at the level of the distal femoral shaft (a straight portion of the femur without the condyles).
Procedure: proximal iPACK
In the distal iPACK group, the participants will receive 20 ml of 0.25% levobupivacaine with adrenaline (1:200,000), injected at the most distal part of the thigh, between the femoral condyles.
Procedure: distal iPACK
● In the distal iPACK group, participants will receive 20 ml of 0.25% levobupivacaine with adrenaline (1:200,000), injected at the most distal part of the thigh, between the femoral condyles.
● In the proximal iPACK group, participants will receive 20 ml of 0.25% levobupivacaine with adrenaline (1:200,000), injected at the level of the distal femoral shaft (a straight portion of the femur without the condyles).
total opioids consumption
total opioids consumption calculated to MME (morphine milligrams equivalent)
Time frame: from surgery until 24 hours after surgery
time to first opioid administration
time to first opioid administration time in hours to first opioid administration after operation.
Time frame: up to 24 hours after surgery
Visual analog scale 6 (rest)
pain intensity will be measured using the Visual Analogue Scale at rest 6 hours postoperatively. The Visual Analogue Scale is a validated, 100-mm horizontal line used to measure pain intensity, ranging from "no pain" (0 mm) to "worst possible pain" (100 mm).
Time frame: 6 hours postoperatively
Visual analog scale 12 (rest)
pain intensity will be measured using the Visual Analogue Scale at rest 12 hours postoperatively. The Visual Analogue Scale is a validated, 100-mm horizontal line used to measure pain intensity, ranging from "no pain" (0 mm) to "worst possible pain" (100 mm).
Time frame: 12 hours postoperatively
Visual analog scale 24 (rest)
pain intensity will be measured using the Visual Analogue Scale at rest 24 hours postoperatively, The Visual Analogue Scale is a validated, 100-mm horizontal line used to measure pain intensity, ranging from "no pain" (0 mm) to "worst possible pain" (100 mm).
Time frame: 24 hours postoperatively
Visual analog scale 6 (flexion)
pain intensity will be measured using the Visual Analogue Scale at 45° flexion in the knee 6 hours postoperatively. The Visual Analogue Scale is a validated, 100-mm horizontal line used to measure pain intensity, ranging from "no pain" (0 mm) to "worst possible pain" (100 mm).
Time frame: 6 hours postoperatively
Visual analog scale 12 (flexion)
pain intensity will be measured using the Visual Analogue Scale at 45° flexion in the knee 12 hours postoperatively. The Visual Analogue Scale is a validated, 100-mm horizontal line used to measure pain intensity, ranging from "no pain" (0 mm) to "worst possible pain" (100 mm).
Time frame: 12 hours postoperatively
Visual analog scale 24 (flexion)
pain intensity will be measured using the Visual Analogue Scale at 45° flexion in the knee 24 hours postoperatively. The Visual Analogue Scale is a validated, 100-mm horizontal line used to measure pain intensity, ranging from "no pain" (0 mm) to "worst possible pain" (100 mm).
Time frame: 24 hours postoperatively
Plan to share: No
No publications or documents are linked to this record.
Started Feb 2025 (actual). Primary completion is estimated for Dec 2026, 22 months after the start.
Of 2,089 non-industry interventional studies with no phase under Pain, Postoperative, half reached primary completion within 11 months of starting (the median), counting those still running; a quarter within 6 and three quarters within 23. This study's planned 22 months is above that.
Counting every sponsor, half of 2,102 studies reached it within 11 months; a quarter within 6 and three quarters within 23.
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